Field of the Invention
The invention relates to a fire-resistant pane, in particular for a fire-resistant glazing assembly, with a protective layer to reduce the clouding of the pane due to aging. Moreover, the invention relates to a method for producing such a fire-resistant glazing assembly and use thereof.
Description of Related Art
Fire-resistant glazing assemblies are known in various embodiments and are used, for example, in the construction industry. They are, as a rule, made of at least two transparent support elements, such as two glass panes, between which a fire-resistant layer made of a transparent, intumescent material is arranged. From EP 0 620 781 81, for example, a fire-resistant layer made of a water-containing alkali polysilicate is known. Under the action of heat on the fire-resistant glazing assembly, the water contained in the alkali polysilicate layer vaporizes and the alkali polysilicate foams up. The transparency of the fire-resistant layer is then greatly reduced, in particular for thermal radiation, and protects for a certain time against unwanted passage of heat. The great expansion of the fire-resistant layer results, as a rule, in the shattering of one of the glass panes and, in particular, in the shattering of the glass pane facing the fire source. Consequently, to improve heat protection and mechanical stability, multiple glass panes are arranged one after another with fire-resistant layers therebetween.
Other, improved fire-resistant layers based on alkali silicate with a particularly high water content from 80% to 90% are, for example, known from EP 0 192 249 A2.
Fire-resistant pane and fire-rated glazing assemblies with such fire-resistant layers often exhibit, over time, points or regions of clouding in the visible range.